Five students from a middle school in the Mississippi town of Ocean Springs have been arrested on suspicion of making threats to shoot up the school, authorities said.
The students are 13-year-old boys, said Marcia Hill, a spokeswoman for the Jackson County Sheriff's Department.
"These threats are no joke, and Sheriff (Mike) Ezell emphasizes investigators take them seriously," the department said in a news release.
The first student was arrested Saturday at a dance at St. Martin Middle School, she said. Other students heard him threatening to shoot up the school for sixth through eighth grades. Four others who allegedly made mass shooting threats, either verbally or on social media, have been arrested, Hill said.
It's unknown if the students are now being held in jail.
Barry Amacker, superintendent of Jackson County Schools, said the last of the alleged threats was discovered Wednesday.
"Law enforcement acted swiftly with the cooperation of the school's administration and the cases were resolved," he said in an email. "In addition to the criminal charges, students are facing disciplinary action from the school district in accordance with school district policy."
People who are convicted of making terrorist threats can face up to 10 years in prison.
Under Mississippi law 97-7-75 the threat must cause "a reasonable expectation or reasonable fear of the imminent commission of an offense."
Not having the ability to carry out the threat is not a defense, the statute says. The law took effect in July.
The suspects have not been identified because they are juveniles. CNN is working to determine whether they have attorneys.
CNN also reached out to Jackson County prosecutors but didn't receive a response.